This invention relates to a portable telephone, suitably a portable radio telephone.
There is a general drive in the field of mobile telephony to produce more compact telephone arrangements particularly for ease of transportation. There is, however, a conflicting, mainly psychological, requirement for a telephone to bridge the gap between the user's tear and mouth to approximate the feel of using a portable radio telephone handset to that of a traditional landline telephone.
One of the ways in which -this has been achieved is by providing a hinged flap attached to the main body of the telephone that is pivoted to a position in which it overlaps the main body when stowed but extends the overall length of the phone when in use. One example of such a phone is found in U.S. Pat. No. 4,845,772. Such phones do, however, tend to be relatively flimsy and prone to damage especially when the flap is open since it is then extremely prone to accidental knocks or other rough treatment. The hinged flap also presents the difficulty of implementing a reliable conductive path from the microphone to the main body of the telephone across the hinge.
Another arrangement that overcomes some of the disadvantages inherent with a hinged flap is described in EP 0 414 365. The compact telephone or handset described in this patent comprises a main body and a cover portion arranged for longitudinal sliding movement relative to the main body. In the retracted position the phone is compact and easy to store. In the extended position the phone is dimensioned such that it comfortably bridges the gap between the user's ear and mouth. The design can be made both compact and relatively robust.
In the handset described in EP 0 414 365 the connection enabling the call answer/send mode is only made when the cover portion is in its fully extended position. Hence the handset can only be used for making or answering a call when the cover is in its fully extended position.